Damping roll for lithographing presses



May 17, 1938. F. BACKOFEN DAMPING ROLL FOR LITHOGRAPHING PRESSES Fild Dec. 13, '1937 INVENTOR. v fivzflanfv 6m M ATTORNEY.

Patented May 17, 1938 I UNITED 'STATES'PATENT OFFICE DAMPING ROLL FOR LITHOGRAPHING PRESSES Fritz Backoten, Mittweida, Germany Application December 13, 1937, Serial No. 179,511

1 Claim. (01. til-67.8)

This invention relates to an improved damping The essential object of my invention is to roll and has for its object to overcome serious make the tube of material, as described, integral disadvantages attendant upon the damping rolls throughout in tube or cylindrical form and free used at the present time. These rolls as made from stretching of any kind. This particular 5 day are made p in roll form from flat pieces object is accomplished by a double weaving in s of material known as Molleton. A manufacwhich certain of the threads, either the warp or ur of s ma al supp i s th lithographer woof thereof, are doubled, that is, in parallelism with sheets or rolls thereof, which are cut into and thereafter the exterior surface of such a p r p s by the li h r ph the n h woven tube or cylinder is subjected to a napping correspon to t phers roll and the operation which imparts to the exterior of the 1.

width corresponding to the circumference of said tube a very soft texture making the same waroll- These p s are en sewed together by a ter-absorbent to a hi h degree, which latter Stitching P ess, are then turned inside out and feature is a highly desirable achievement in thereafter the stitching is subjected to a hamtubes of this kind. The essence of my invenmering operatiorrin order to make the stitched tion, therefore, is to provide a fully napped, l5

abutting ends with their stitches Somewhat thindouble woven, seamless Lube integral throughout in p h o thickness t an the remainin and of substantially the same size as thelithopart of the tube of this material. Such a tube graphing roll in order to obtain a snug fit, and

is then p Over a t aph g r which roughened only on the exterior to form a thick has been provided with a felt covering, as well nan The t r hi plates are not marked by wn The P rt n f the tub h mm r any ridges or any ribbed effect, when the imdown is somewhat of less depth or thickness than proved tub i u ed.

e rem i n part of the tub of m rial, These and additional features of the invention therefore the Stitched Portion s no effect P will be hereinafter described, with the aid of the lithographing process carried. out.v the accompanying drawing; and the invention a There a e y disadvantages in the use Of will be finally pointedout in the appended claim. such tubes. First, the lithographer must cut up I t accompanying drawing: his blanks, as before stated, must have them Figure 1 shows a side view in perspective of a sewed, d t is Sewing Operation Consumes 6011- seamless, double woven tube which is about 7 slderable time, and the tube thus formed is not inches i d meter, and about 50 inches long; attendant with a degree of certainty that the Figure 2 1 section taken on line z z of e will P p y hug the lithographing rOllure 1, showing, however, the method of double It has also been found that certain stretching weaving i greatly enlarged f rm, and only t s p a wh n n th e ap e roll. a showing one line of thread formation, it being therefore steps have been taken to compensate understood that the other threads are disposed a for such stretching, as set forth in Patent No. in h same b t, s t ff, in the known 1,281,940, dated October 15, 1918, but as far as th d f weaving; and r .lmown, devices under this patent are not on the Figure 3 1s plan view of part of t American market, because unsatis cto yproved tube, to show the end threads, the woven 40 The object of my present invention is to overpart. and t napped portion,

C e t e y disadvantages incident to tubes Similar characters 'of reference indicate corof this kind, and cons sts in mak a tube for responding parts throughout the various views.

lithographing rolls wovenin a manner that the Referring t t drawing, and more particularentire tube is formed and the diameter of which 1y to Figure 1, the tube there shown is about 59 is substantially equal to the diameter the inches long and7inches in diameter. Aplan view lithographing roll to which the tube is to be apof t t b is shnwn i part, in Figure 3, in t t plied so as to maintain a snug fit therewith. part, i i at d by b, c and d; th other part In this tube no stretching takes place and it is' on the left of the line a-d being cut away. A

integral throughout,- The tube is pp ver plan view of the woven part is shown in the part the lithographing roll and fits snugly thereon. a--e,fd, and the threads ar shown by C. The i The free ends of the cylinder or tube are then portion ab--c-d is mapped or roughened, joined together by a series of -cross-..titchings at which results from the action of a series of hookeach end of the lithographing roll by which they shaped devices acting on the woven portion, as are held securely on the roll in a well-known shown by a-e--,f-d. These devices go to and manner. i'ro as shown by the arrow 6.

In Figure 2 isshown the method of double weaving. The thread begins at A and ends at B. The woof threads are shown by C. The thread beginning at A passes over the first woof thread 0, then under four warp threads C, then over the fifth, then under four, and so on, until it has completed one revolution, when at D it passes over three, then under one, then under four, then around the circumference to B. Thereby a double weave results. The actions described are, of course, repeated to any length of tube, and the special movement of thread under one and over four is one formof weave. The essential thing here is the double weave, in order to have the tube stand the napping, which is not possible with a single weave, since roughing it on both sides would so weaken a single thread as to break it down. With a double weave as shown for example, only one side of a thread is roughened, and thereby the strength of the thread is maintained. In the drawing, Figure 2, the spaces EF are naturally filled by the adjacent threads. While the roughened part is only on the surfaces of the threads, nevertheless, if two or more opposite surfaces of the same thread are roughened the thread becomes so weakened as to break. v

The double weaving works out a diagonal weave as shown in Figure 3. More important is the double weave of a seamless tubing for damping rolls for lithographing presses.

The threads used are a good'grade of cotton. The tubes are woven any length, about 30 yards long, and are then cut off according to demand. The seamless tube saves much time and money in applying the seamless tube to the roll.

It will be seen that a double weave, seamless tube, having its exterior and interior surfaces napped or roughened has been produced, the threads of the double weave being so interconnected as to produce in effect one single structure.

It is obvious that various changes and modifications may be made in the details of construction and design of the above specifically described embodiments of this invention without departing from the spirit thereof, such changes and modifications being restricted only by the scope of the following claim:

What is claimed is:

A damping roll for lithographing presses, comprising a seamless double weave interconnected woven material, joined integrally throughout in tube form with a substantial nap at the exterior and interior portions thereof, and having a diameter substantially equal to the diameter of the lithographic roll to which the damping roll is to be applied and a length somewhat greater than the length of such roll, the nap being only on one side of a thread.

FRITZ BACKOFEN. 

